CVE-2026-103001
PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse
Impact
PyJWT is a Python implementation of JSON Web Token standards. From 2.11.0 through 2.13.0, PyJWT's PyJWT._merge_options() method can modify a caller-supplied mutable options mapping when verify_signature is false. If an application reuses that same mapping for a later decode() or decode_complete() call and changes verify_signature to true, the mapping can retain false values for expiration, not-before, issued-at, audience, issuer, subject, and JWT ID checks. A signed token with invalid registered claims can then be accepted without disabling signature verification, but applications that create a fresh options mapping for each call are not affected.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | PyJWT | >= 2.11.0, <= 2.13.0 | none recorded |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pyjwt Project | Pyjwt | from 2.11.0 before 2.13.0 |